This Civil War trilogy covers the history of just one of the Union armies - the Army of the Potomac, to which Robert E. Lee would eventually surrender - and Volume Two, The Glory Road, covers just seven months, from Fredericksburg to Gettysburg.

So the coverage is unusually detailed, revealing many aspects of the war that we would normally miss. For example, we always knew that Burnside was defeated at Fredericksburg because his pontoons had gone astray, preventing him from crossing the Rappahannock. But here we get the whole miserable story, a freak conjunction of errors, misunderstandings, rivalries, bureaucratic apathy and sheer ill fortune, as though the fates had decided to curse the entire venture. Through Catton’s vivid prose, we can almost feel the whole clumsy system congealing into inertia, and sympathise heartily with the luckless Burnside. We also knew that he was planning to lead a second attack, supposedly a mark of bravery, until talked out of it by his colleagues. But Catton suggests that it may actually have been a suicide plan by this highly conscientious leader, troubled by survivor guilt.

Joe Hooker’s sudden loss of nerve at Chancellorsville is something else that we know about, but have never heard explained. It is illuminating to follow the various stages of shock and confusion, interspersed with vain attempts to show signs of his old optimism.

Again, we knew that front-line pickets would swap more than just insults with their opposite-numbers in the enemy lines on a dull night. Small consignments of coffee or rice would be (illegally) exchanged across narrow rivers on paper boats. So would little gems of wisdom. A Confederate sentry explained “You don’t hate us, the way we hate you” - a possible rationale for how the war lasted so long, after the south should logically have given up.

There is just one drawback to this vast quantity of detail. It makes it hard to maintain an overview of the battles, especially if your download is text-only (no maps), as mine is. But on balance, I’ll willingly settle for this.